Becks did a test plot with varying combinations of adding sugar to starter fertilizer and in some cases gaining 3 to 6 bushel per acre and a up to $22/acre return on investment. Dextrose or sugar is cheap and it gets soil microbes super charged to break down nutrients already in the soil.  In these pencil sharpening times, definitely something to consider.  In the past I`ve thought about it but wondered if it wouldn`t attract maggots and other seed bugs.  I`ve been cautioned about spreading manure before planting that maggots possibly attack the seed.